JP3439619B2 - Method and apparatus for discharging molten base metal in electric melting furnace - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric melting furnace for heating and melting solid waste such as incineration ash from a refuse incinerator and construction waste by utilizing electric energy such as arc and plasma. The present invention relates to a method and an apparatus for discharging molten base metal in an electric melting furnace that discharges the base metal contained in the bottom.

[0002]

2. Description of the Related Art Conventionally, in an electric waste melting furnace, a molten base metal layer is formed on the bottom of a furnace body and slag is extracted by an overflow method. Metals are often contained in the waste, and due to this accumulation, the molten base metal layer rises gradually, and the molten slag layer is reduced, and as a result, the residence time of the molten material is reduced and the molten base metal layer is completely reduced. There is a risk of spillage without being dissolved. Therefore, the furnace body is tilted periodically to discharge the molten base metal.

[0003]

In some cases, the slag extraction port and the molten base metal extraction port are formed separately, but when the molten slag is extracted from the slag extraction port, the molten base metal is put into a slag cooling water tank. It is then cooled and solidified, and is taken out from the slag cooling water tank as a solidified metal mass by a discharge conveyor that also serves as granulated slag.

In this case, the slag cooling water tank has a cooling water supply port formed near the dropping position, but the molten base metal dropped into the cooling water does not solidify immediately but spreads to the bottom and then solidifies. And then formed a large lump. As a result, there are problems that a trouble occurs in the discharge conveyor, the water tank is damaged, and it is difficult to handle the solidified metal after it is taken out.

In the invention according to claim 1 of the present invention, the above problems can be solved, and the solidified metal to be water-cooled and solidified can be formed into a small lump or a granular form so that no trouble occurs in the metal carrying-out means and handling is also possible. An object is to provide a method and an apparatus for discharging molten base metal in an electric melting furnace which is easy.

[0006]

In order to achieve the above object, the method of discharging molten base metal in an electric melting furnace according to claim 1 of the present invention is a base metal housed in the bottom of an electric melting furnace. the upon discharged in the molten state, with dropping the molten base metal into the cooling water, soluble
Shallow base metal drop point under cooling water
Toward, the momentum melts at a flow velocity of 10 m / sec or more
3 times more cooling water than 9.2 times the falling momentum of the base metal
It is sprayed from above the direction to disperse the molten base metal to accelerate the cooling and form the solidified metal in the form of small particles or particles.

A molten base metal discharging device for an electric melting furnace according to a fourth aspect is installed in a discharging path for discharging the molten base metal contained in the bottom of the melting furnace to cool the molten base metal. A discharge device for molten base metal in an electric melting furnace for solidification, a cooling water tank arranged in a drop discharge route of the molten base metal,
A shallow position below the surface of the cooling water at the falling point of the molten base metal
Toward the side, the momentum melts when the flow velocity is 10 m / sec or more.
More than 9.2 times more cooling water than the falling momentum of molten base metal
It is equipped with three or more jet nozzles for jetting, and a metal carrying-out means for taking out the solidified metal from the cooling water tank.

According to each of the above structures, by injecting the cooling water into the molten base metal discharged and dropped in the cooling water in the cooling water tank, the molten base metal is separated and dispersed to increase its surface area and the cooling water is supplied at high speed. It can be circulated by contact with and can be separated and solidified into small lumps. Therefore, trouble does not occur in the metal carrying-out means, and handling after taking out from the cooling water tank becomes easy.

According to a second aspect of the present invention, in the above structure, the cooling water is arranged on a horizontal plane having a predetermined depth.
It is ejected from an ejection nozzle .

According to the above construction, the solidified metal can be surely formed into a small lump shape. Further, in the invention according to claim 3, the jet cooling water has a flow velocity of 12 m / sec and its momentum is 11 times or more of the falling momentum of the molten base metal.

According to the above construction, the solidified metal can be surely formed into a small lump shape or a granular shape.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Here, an embodiment of a melting furnace according to the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, a furnace body 3 is disposed on a pedestal 1 via a base metal discharging tilting device 2 that can be tilted about a support pin 2a by a tilting cylinder 2b. On the bottom wall 3a of the furnace body 3, a metal housing 5 for housing the base metal DM is formed. An ash supply port 6 for injecting incinerated ash A onto the base metal DM of the furnace body 3 is formed in the front wall portion 3b of the furnace body 3 on the tilting cylinder 2b side,
An ash supply hopper 7 and an ash pusher 8 are provided facing the inlet of the ash supply port 6. Further, a slag discharge port 9 for discharging the molten slag melted on the base metal DM is formed in the rear wall portion 3c of the furnace body 3 on the support pin 2a side,
The slag discharge port 9 and its drop path are covered with a discharge passage cover 10. The slag discharge port 9 also serves as a discharge port for the base metal DM, and the discharge passage cover 1
A slag cooling device 11 for cooling the molten slag and the molten base metal with water to generate water granulated slag and solidified metal CM is disposed below 0. Further, a preheating burner 12 is arranged on the discharge passage cover 10 so as to face the slag discharge port 9.

The upper part of the furnace body 3 is covered with a water cooling jacket 13 and two torch insertion ports 14 are provided on the ceiling wall 3d.
Anode torch 1 which is a plasma torch through A and 14B
5A and a cathode torch 15B are vertically provided, and both plasma torches 15A and 15B are supported by a torch elevating device so as to be vertically movable. A direct current power supply device (not shown) and a working gas supply device (not shown) are connected to both plasma torches 15A and 15B. An exhaust gas port 16 is formed in the side wall portion 3e of the furnace body 3 and is connected to the exhaust gas treatment device.

The slag cooling device 11 is also used for cooling the molten base metal DM, and is provided with a cooling water tank 21 having a horizontal bottom plate 21a and an inclined bottom plate 21b, and water granulation provided along the horizontal bottom plate 21a and the inclined bottom plate 21b. A carry-out conveyor device 22 which is a metal carry-out means capable of discharging the slag and the solidified metal CM, and three jets for jetting the cooling water toward the falling position X of the molten base metal DM at a relatively shallow position below the cooling water surface WL. It is composed of nozzles 23A to 23C.

The carry-out conveyor device 22 includes a cooling water tank 2
A pair of left and right endless chains 22b arranged along the bottom portion of the sprocket 22a via a sprocket 22a;
It consists of a scraper conveyor equipped with a plurality of scrapers 22c, which are hung across the 2b at regular intervals in the length direction, and a drive motor 22d. It can be scraped out along the inclined bottom plate 21b.

The injection nozzles 23A to 23C are provided with a cooling water surface W.
The injection nozzles 23A at the center are respectively arranged on the horizontal planes of a predetermined depth below L, and the injection nozzles 23B and 23C on the left and right are arranged on both sides in the injection direction of the injection nozzle 23A. It is arranged so as to jet toward the drop position X at a predetermined angle. Two
Reference numeral 4 denotes a drain port formed in the central portion of the side plate 21c of the cooling water tank 21.

In the above structure, when the metals contained in the ash and the waste to be melted are melted and the amount of the base metal DM is increased, the operation of the melting furnace is stopped, the tilting device 2 is driven, and the furnace main body 3 is slightly moved. Incline and first melt base metal DM
Most of the molten slag above is discharged. Then, the furnace body 3 is further tilted to discharge the molten base metal DM from the slag discharge port 9 and discharge and drop it into the cooling water tank 21. At this time, the cooling water is jetted from the jet nozzles 23A to 23C at a predetermined flow rate with momentum, and the jetted cooling water collides with the jetted water at the same time to separate the molten base metal DM into small pieces or particles, Distributed. Thereby, the surface area of the molten base metal DM is increased and the cooling water is circulated quickly, so that the molten base metal DM is extremely effectively cooled and solidified, and the solidified metal CM is a small lump (diameter 8 to 15).
mm, height 50 mm bell-shaped) or granular (diameter 5 ~
It becomes a spherical shape of about 8 mm).

By the way, a cooling water jet flow capable of forming the molten base metal DM in the form of small lumps or particles has been confirmed by experiments as shown in FIG. That is, the flow velocity of the cooling water jet flow is changed to 5, 10, and 18 m / sec, and the flow rate of the cooling water at this time is set to the value of the cooling water jet flow with respect to the momentum (m × v) of the molten base metal DM discharged and dropped. The ratio with the momentum (m × v) is 4.6, 9.2, 11.0, respectively.
Is set so that Further, the number of the injection nozzles 23A to 23C at this time is changed to 1 to 3.

According to the above experimental results, if the flow velocity of the cooling water jet flow is 10 m / sec and the momentum ratio is 9.2 times,
The solidified metal CM could be formed into a small lump in the case of using the one injection nozzles 23A to 23C. Further, when the flow velocity of the cooling water jet flow is 12 m / sec and the momentum ratio thereof is 11.0 times, the number of the injection nozzles 23A to 23C is one or two, and the solidified metal CM can be made into a small lump, and further three The thing using the injection nozzles 23A-23C was able to make the solidified metal CM granular.

Therefore, the flow velocity of the cooling water jet is set to 10 m.
/ Second or more, the momentum ratio becomes 9.2 times or more,
Moreover, the solidified metal DM can be formed into a small lump shape by using three or more injection nozzles. Furthermore, when the flow velocity of the cooling water jet is 12 m / sec or more, the momentum ratio is 11.
When the flow rate is 0 times or more, the solidified metal CM can be formed into a small lump even with one injection nozzle,
Further, it has been found that the solidified metal CM can be formed into particles by using three or more injection nozzles.

According to the above embodiment, the injection nozzle 23 is applied to the molten base metal CM below the surface of the cooling water discharged and dropped.
Since the jet streams of the cooling water are collided from A to 23C, the molten base metal DM can be effectively separated and dispersed to promote the cooling, and the solidified metal CM can be formed into a small lump shape or a granular shape. Therefore, the solidified metal CM taken out from the cooling water tank can be easily handled without causing any trouble.

In the above embodiment, the base metal discharge port is also used as the slag discharge port 9 and the slag cooling device 11 is used to cool the molten base metal DM. Can also be installed separately to provide their own cooling device.

Further, in the above embodiment, the injection nozzle 23
Although the number of A to 23C is three, it may be singular, two, or four or more.

[0024]

As described above, according to the method and apparatus for discharging molten base metal in the electric melting furnace according to the first and fourth aspects of the present invention, the molten base metal discharged and dropped in the cooling water in the cooling water tank. By injecting the cooling water into, the molten base metal can be separated and dispersed to increase the surface area thereof, and the cooling water can be contact-circulated at a high speed and separated and solidified into a small mass. Therefore, it is possible to prevent the trouble of the metal carrying-out means and the damage of the cooling water tank, and the handling after taking out from the cooling water tank becomes easy.

According to the second aspect of the present invention, the solidified metal can be reliably formed into a small lump. Further, according to the third aspect of the invention, the solidified metal can be reliably formed into a small lump shape or a granular shape.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an embodiment of a melting furnace according to the present invention and showing a molten metal discharged state.

FIG. 2 is a plan view of the melting furnace.

FIG. 3 is a chart showing the results of a cooling water injection experiment in the same melting furnace.

[Explanation of symbols]

2 Tilt device 3 furnace body 9 Slag outlet 10 Discharge passage cover 11 Slag cooling device 15A, 15B Plasma torch 21 Cooling water tank 22 Carry-out conveyor device 23A-23C injection nozzle DM base metal CM solidified metal WL cooling water surface X Fall position

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jiro Sakata 5-3-8 Nishikujo, Konohana-ku, Osaka City, Osaka Prefecture Hitachi Shipbuilding Co., Ltd. No. 3-28 Hitachi Shipbuilding Co., Ltd. (56) Reference JP-A-7-301496 (JP, A) JP-A-62-172107 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B09B 3/00-5/00

Claims (4)

(57) [Claims] Upon the 1. A electric base metal contained in the furnace bottom portion of the melting furnace is discharged in the molten state, with dropping the molten base metal into the cooling water, melt Besumeta
Toward the shallow position below the surface of the cooling water at the drop point of
Momentum of molten base metal with flow velocity of 10 m / sec or more
9.2 times or more of the falling momentum of cooling water from 3 or more directions
A method for discharging a molten base metal in an electric melting furnace , which comprises injecting, thereby dispersing the molten base metal to accelerate cooling, and solidifying the metal to form a small lump or a grain. 2. The cooling water is distributed on a horizontal surface having a predetermined depth.
The method for discharging a molten base metal in an electric melting furnace according to claim 1, wherein the discharging is performed from an installed injection nozzle . 3. A molten base metal in an electric melting furnace according to claim 1, wherein the jet cooling water has a flow velocity of 12 m / sec or more and a momentum of 11 times or more of a falling momentum of the molten base metal. Ejection method. 4. An apparatus for discharging a molten base metal in an electric melting furnace, which is installed in a discharge path for discharging a base metal stored in a bottom portion of a melting furnace in a molten state to cool and solidify the molten base metal. A cooling water tank placed in the drop discharge path of the base metal and a shallow position below the surface of the cooling water at the drop point of the molten base metal
Toward the side, the momentum melts when the flow velocity is 10 m / sec or more.
More than 9.2 times more cooling water than the falling momentum of molten base metal
An apparatus for discharging a molten base metal in an electric melting furnace, comprising: three or more injection nozzles for injecting; and a metal carrying-out means for taking out solidified metal from the cooling water tank.